Improvement in mining-tools



UNITED STATES PATENT OFFICE.

JOSEPH GIFFORD AND ISAAC eIFFonD, or nns MoINEs, IOWA.

IMPROVEMENT IN MINING-TOOLS.

Specification forming'part of Letters Patent N0. 220,070, datedSeptember 30, 1879; application filed March 27, 1879.

To all whom it may concern:

Be it known that we, J OSEPH GIFFORD and ISAAC GIFFORD, of Des Moines,in the county of Polk and State of Iowa, have invented an lmprovedMining-Tool for Forming a Powder- Chamber in the Bottom of a Bore, ofwhich the following is a specification.

Our invention relates to that class of tools that are designed to beoperated in a bore formed by a rock-drill, for the purpose of enlargin gthe diameter of the bottom of the bore and forming a powder-chamber, asameans of diminishing to the minimum the labor and explosive materialrequired in mining and quarryin g by the drilling and blasting process.

It consists in forming a removable end-piece for a tubular shaft insections, and combining therewith a duplex cutter in such a manner thatthe cutter can be readily adjusted and actuated by means of operatingdevices mounted at the top end of the shaft to cut simultaneonsly upwardand downward to produce a spherical chamber at the bottom of the bore,

as hereinafter fully set forth.

Figure 1 of our drawings is a perspective view, showing our completetool inserted in a bore. Fig. 2 is a side view of our removableend-piece, having parts broken away to show the manner of forming andcombining the sections. struction, application, and operation of ourcomplete invention.

Ais a tubular metal shaft, that may vary in size, as desired. It hasbranches 1) 1) near its top end, that form sockets for hand-levers o c.

B represents our removable end-piece, form ed in two parts. 4" is theminor part, secured to the major part bymeans of dowels s at its topend, and a set-screw, 2:, at its lower end. t is thepivot upon which theduplex cutter is placed and operated. This pivot may be formed integralwith one of the parts, or it may be attached in any suitable way.

The complete end-piece B is tubular, and has. slots in its sides,through which the pivoted cutter extends and moves. It is rigidlysecured to the lower end of the shaft A by means of a screw or in anysuitable way.

f is the duplex cutter or reamer, placed on the pivot it before the partr was fixed in place,

Together they clearly illustrate the'conin such a manner that itscutting-edges incline in opposite directions. 9 is a rod linked to thepivoted cutter f. It extends upward through the shaft A. h is a capfitted to the top of the shaft,and secured thereto by means ofset-screws *5 t, or in any suitable way. It has an opening that forms abearing for a short rod, 9, that passes downward through the cap. 70 isa hand-wheel fixed to the top end of the short rod g. l is anenlargement or collar formed on or fixed to the same rod g. m is a loosecollar, through which this same rod 9 is passed downward. The screws 1',that fasten the cap it to the top end of the shaft A, penetrate thiscollar m, and retain it in a fixed position relative to the shaft andcap, to engage the collar 1 on the rod 9, as required, to prevent anyvertical movement of the rod g.

a is a sliding block, that has flanges or beads at its sides, that entercorresponding grooves, slots, o r bearings formed in the sides of theshaft A. The ends of the rods g and g are screwed into the sliding blockn, in such a manner that the combined rods can be readily lengthened andshortened, by means of the sliding coupling, by simply turning thehandwhe'el k, that is fixed to the top end of the short rod g".

In the practical operation of our improved mining-tool, the cntte r;f isadjpsted so that its ends do npt ,,project outside of the ifeiioyableend-piece B. Thetubular shaft can then be set into a bore ofcorresponding size that was previously drilled into a bed of coal orother substance that can be drilled and broken by means of powder.

When our tool is thus placed, the cutter can be readily adjusted so asto make its ends project through the slots in the e'nd-pieceB fromopposite sidesone from the top portion to cut downward, and one from thelower portion to cut upward-as the complete tdol is revolved, and asrequired to cut a spherical chamber in the bottom 'of the bore. Turningthe handwheel is to revolve the rod 9 will impart vertical motions tothe sliding block or coupling a, and thereby move the rod'g up and down,as required, to adjust the cutter f on its pivot 19. By thus properlyadj u'stin g the cutter and revolvin; the complete tool by means of thehand-levers c, a powder-chamber can be readily out in the bottom of abore, and a given quantity of powder or other explosive material packedtherein to do better execution than would result from placing, andexploding it in a bore that has no chamber, and much time, labor, andexplosive materials saved in mining and quarrying operations.

I claim- 1. In a miningtool, the removable end-piece B, having adetachable section, 1', dowels s, and a pivot, t, and slots atitssides,adapted to receive and pivot an adjustable cutter, substantially as and for the purposes shown and described.

2. The combination of the end-pieee B r s t and the duplexcnttcrf,substantially as shown and described, for the purposesspecified.

JOSEPH GIFFORD.

ISAAC GIFFORD.

Witnesses:

ERASTUS W. SMITH, FRANK W. IIEERS.

